CAPITAL CONSTRUCTION FUND (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
CAPITAL CONSTRUCTION FUND
Maximum period to commit fund deposits for qualified purposes	25 years
Period over which deposits will be treated as non-qualified withdrawals	5 years
Accounts receivable, net	$ 256.8	$ 268.9
Eligible Accounts Receivable Assigned to CCF
CAPITAL CONSTRUCTION FUND
Accounts receivable, net	$ 82.3	$ 178.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

Name:	matx_CapitalConstructionFundLineItems
Namespace Prefix:	matx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum period from the date of deposit to commit deposits for qualified purposes.

+ References

No definition available.

+ Details

Name:	matx_MaximumPeriodToCommitFundDepositsForQualifiedPurposes
Namespace Prefix:	matx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The period over which deposits not committed for qualified purposes longer than the maximum specified period from the date of deposit will be treated as non-qualified withdrawals.

+ References

No definition available.

+ Details

Name:	matx_PeriodOverWhichDepositsWillBeTreatedAsNonQualifiedWithdrawals
Namespace Prefix:	matx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481372/852-10-55-10

+ Details

Name:	us-gaap_ReceivablesNetCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_TradeAccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: